Dye for photographic layers



Patented Sept. 8, 1942 UNITED STATES QPATEN T "OFFICE;

DYE FOR rno'roolmrniomrnns Burt H. Carroll and Jonas John Chechak, Rochester, N. Y.,' assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. 7 Application May 7, 1940, Serial-No. 333,866

This invention relates to photography and particularly to azo dyes for incorporation in photographic layers.

dyes used in photography layers in which they are cause of the tendency to diffuse from one layer to another. Such wandering may sometimes be prevented by precipitating the dyes with organic bases although this method of rendering the dyes non-diffusing has the disadvantage of 'increasing the cost of preparing the dye layers and frequently makes the incorporation of a. sufficient concentration of the dyes diflicult owing to a tendency for the dye and the precipitate to separate out in crystals or flakes.

Azo dyes are, in general, desirable for use in coloring photographic layers because they are relatively light stable and may be decolorized by suitable treatment of the film. It has previously been thought that direct cotton dyes may be used to color photographic gelatin layers and that such dyes do not diifuse from the layers. However, we have found that this is not necessarily truefin general.

It is, therefore, an object of the present invention to provide photographic layers having dyes which do not difluse through set gelatin or which diffuse only very slightly. Afurther objectis to provide dyes which layers in which they are incorporated 'or which are coated adjacent to the dye-containing layers. Astillfurther object is to provide dyes for color photography which can be bleached readily in.

the presence of a silver image by the use of suitable bleaching agents. A still further object is to provide image-forming dyes for color photography which have the proper spectral absorption. Other objects will appear from the following description of our invention.

These objects are accomplished by the 1ise of azo dyes made by tetrazotizing symmetrical aromatic diamines having certain substituent groups ortho to the amino groups and coupling them of the dyes which havev do not desensitize emulsion to those specifically mentioned.

\ 4 12 Claims. (01. 95-6) with fl-naphthols which may or may not contain substituent groupsl'f' These dyes are formed from symmetrical aromatic diamines containing alkyl orhalogen substituents in the positions in the aromatic nuclei ortho to the amino groups. These diamine bases are tetrazotized in the usual way using 'anyknown diazotizing reaction and are then coupled with a s-naphthol. Since in a B-naphthol the position para to the hydroxyl group is substituted, the coupling takes place in theaor l-position of the naphthol molecule. Aromatic diamines suitable for use in the production of the dyes which we propose touse are .ortho tolidine, ortho tolidine disulfonic acid,

4,4-diaminostilbene disulfonic acid, ortho dichlorbenzidine, 4,4-diamino-3,3'-dimethyl e diphenylmethane, and 4,4-diamino-3,3'-dichlorodiphenylurea. B-naphthols suitable for use in the coupling reactionare fl-naphthol and o-naphthol-3,6-disulfonic acid. Amino substituted ,9- naphthols may also be used and the amino groups may contain acyl substituents. The acyl group may contain a straight carbon chain of from 1 to 12 carbon atoms or a branchedcarbon chain such as isopropyl, isobutyl and secondary or tertiary amyl. These long chain tend to decrease difiusion of the dye.

The dyes which we contemplate have the following structure:

acyl groups using may X=halogen or alkyl Y==chemical bond -NH-CO-NH --CH=CH-- -(CH2)qwhere Z=hydrogen, alkyl,

q is a positive integer alkoxy, sulfonic acid, car- In the above .formula it isunderstoodthat tha aryl radicals, including the fi-naphthol groups, may contain other substituent groups in addition We propose to use may be incorporatedin filter overcoats, overcoats or interlayers graphic films, plates or paper or they may be mixed with unsensitized or optically sensitized The dyes which in photoemulsions and employed in the preparation of multi-layer fiims for color processes in which the image is formed bydestruction of a portion of a 4,4' -diamino-3,3'-dimethyldiphenylmethane and coupling it in alkaline mediumwith'2 molsof 'p-naphthol-3,6-disulfonic acid (commonlyknown as R acid) has the following structure;

solNa on on H: on 50.1w."

Example 2 The dye made by" tetraz ot'iz'ing 1 mol of 3,3'-di chlorbenzidine and coupl it in alkaline mediumwith 2 .mols oi! 'p-naphthol-8-sulfonic acid has the foilowing structure:

- -c1- ,on

yolnflg no;

Ezlrarnple 3 I I The dye made by tetrazoti'zing 1 mol of '5,5-dimethylbenzidine-2,2f-disulfonic acid and coupling it in alkaline medium with 2 molsof p-naphthol'has the following structure; 3* '11 rm" on;

When used as image-forming dyes in sensitive photographic layers, the dyes which we have describedmay be used with a photographic'm'aterial such as that of Christensen U. '8. Patent 1,517,049, granted November 5, 1924. In'the material described in the Christensen patent, the sensitive layers are-uniformly colored a color complementary to that which they are designed to record. The blue-sensitive-layer is colored yellow, the green-sensitive layer is colored magenta and the red-sensitive layer is'colored bluebleaching solutions such as alkaline stannous chloride. The dye may be bleached in the presence of a silver salt image rather than in the presence of a silver image.

Although the specific dyes which we have described are magenta or yellow in color, dyes or these colors being used in the well known process of subtractive color'photography, we are not limited to dyes of these hues as dyes of other colors may be formed by our invention for use in photographic layers.

Dyes of the structure which we have described are practically non-diffusing in gelatin and have little or no adverse eflect on the sensitivity of the emulsion in which they are incorporated 01 0!1 adjacent emulsion layers. They may be bleached in the presence of a silver or silver salt image as stated above and when used in which have. sharper absorption-spectra, that is which absorb more completely in one spectral region andless in other spectral regions. "The dyes which we have proposed havehigh water solubility, thus facilitating the preparation I of dyed layers of adequate dye densityv without crystallization of the dye. In general, the dyes may contain substituentgroups other than those stituted'with a large number ofsolubilizing groups or. their. diffusion tendency will be increased. For example, some of the dyes might be made to ,difiuse by introducing an excessive 'nurnberof sulfonic acid groups. This fact is well known in the dye art and we do not intend toinclude within the scope of our invention dyes 3 containing an excess number of solubilizing groups which would increase the diffusion tendgreen. However, the dyes used according to our invention may also be incorporated in sensitive layers which transmit the color of the imageforming dye. For example, the magenta dyes proposed according to our invention may be incorporated in a blue-sensitive layer or a redsensitive layer as well as in a green-sensitive layer of a multi-layer coating.

Our dyes maybe incorporated in sensitive to use may be bleached in suitable alkaline 'ency. In general, dyes having two to four sulfonic acids in the molecule are sufiiciently soluble and do not diffuse from gelatin. However, even with dyes containing more than four sulfonic acid groups the diffusion tendency may be re ducedby various expedients such as acylation of amino'groups or ,etherification or esteriflcation of hydroxyl groups other than those ortho to the azo group. p a

It is to be understood that the specific examples included herein are illustrative only and thatsour invention is to be taken aslimited only by. the scope of the appended claims.

We claim; 1 I

l. A multi-layer photographic element including a light-sensitive gelatino-silver halide layer and a gelatin layer containing a non-diffusing dye formed by tetrazotizing a symmetrical aromatic diamine. having ortho to the amino groups,

substituent groups selected from the class consisting of halogenand alkyl groups and coupling it in the 1-position with a B-naphthol.

2. A multielayer photographic element including a light-sensitive gelatino-silver halide layer and a. gelatin layer containing a non-diffusing dye formed by tetrazotizing a symmetrical aro- Y matic dianiine having halogen groups ortho to dye formedby tetrazotizing a symmetrical arothe amino groups and coupling it in the l-posimatic diamine having alkyl groups ortho to the amino groups and coupling it in the 1-position with a B-naphthol.

4. A multi-layer photographic element including a light-sensitive gelatino-silver halide layer and a gelatin layer containing a non-diffusing dye formed by tetrazotizing a symmetrical aromatic diamine having halogen groups ortho to the amino groups and coupling it in the l-position with B-naphthol.

5. A multi-layer photographic element including a light-sensitive gelatino-silver halide layer and a gelatin layer containing a non-diffusing dye formed by tetrazotizing a symmetrical aromatic diamine having alkyl groups ortho to the amino groups and coupling it in the 1.-position with -naphthol.

6. A multi-layer photographic element including a light-sensitive gelatino-silver halide layer and a gelatin layer containing a non-diffusing dye formed by tetrazotizing a symmetrical aromatic diamine having chlorine groups ortho to the amino groups and couplin it in the l-position with B-naphthol.

'7. A multi-layer photographic element including a light-sensitive gelatino-silver halide layer and a gelatine layer containing a non-difiusing dye formed by tetrazotizing a symmetrical aromatic diamine having methyl groups ortho to the amino groups and coupling it in the l-position with B-naphthol.

8. A gelatino-silver halide layer for the bleachout process of color photography uniformly collayer which is uniformly colored with a dye formed by coupling a tetrazotized symmetrical aromatic diamine having halogen groups ortho to the amino groups, with a B-naphthol.

11. A multi-layer element for color photography having at least one gelatino-silver halide layer which is uniformly colored with a dye formed by coupling a tetrazotized symmetrical aromatic diamine having alkyl groups ortho to the amino groups with a B-naphthol.

12. A multi-layer element for color photography having at least one gelatino-silver halide layer which is uniformly colored with a nondiflusing dye formed by tetrazotizing a symmetrical aromatic diamine having ortho to the amino groups, substituent groups selected from the class consisting of halogen and alkyl groups, and coupling it in the 1-position with a B-naphthol.

BURT H. CARROLL. JONAS JOHN CHECHAK. 

